Tube-testing apparatus



May 16, 1950' w. H. GERSTENSLAGER' TUBE-TESTING APPARATUS 5 Sheets-Sheet 1 Filed Sept. 25, 1947 INVENTOR WILLIAM H. GERSTENS LAGER FIG. 5

ATTO RN EY y 6, 1950 w. H. GERSTENSLAGER 2,508,246

TUBE-TESTING APPARATUS 5 Sheets-Sheet 2 Filed Sept. 25, 1947 1 l Vmwmv FIG. 3

FIG. 2

INVENTOR WILLIAM H. GERSTENSLAGER ATTORNEY w. H. GERSTENSLAGER 2,508,246

May 16, 1950 TUBE-TESTING APPARATUS,

5 Sheets-Sfieet 3 Filed Sept. 25, 1947 FIG. 6

4 INVENTOR. WILLIAM H. GERSTENSLAGER FIG. 4

ATTORNEY y 6, 1950 w. H. GERSTENSLAGER 2,508,246

TUBE-TESTING APPARATUS Filed Sept. 25, 1947 5 Sheets-Sheet 4 FIG. 8 :24

me I20 I27 |28 INVENTOR WILLIAM H. GERSTENSLAGER BY W ATTORNEY w.- H. GERSTENSLAGER ,508,2 6

TUBE-TESTING APPARATUS 5 Sheets-Sheet 5 ATTORNEY May 16, 1950 Filed Sept. 25, i194"! INVENTOR. WILLIAM H. GERSTENSLAGER 5 M M w v 5 9 S 1 c mm Wm um. 6 F 0 UV m 4H m 120 1 f SUPPLY lsl Y 22mm FIG. l0

Patented May 16, 1950 UNITED STATES PATENT OFFICE William. H. Gerstenslager, Akron, Ohio, assignor to Wingfflot Corporation, Akron, Ohio, a corporatiomo'fDelaware Application -September 25, 1 94371, Serial N 0'. 776,085

1.4 Claims. 1

ihis invention relates to an apparatus for testing inflatable bodies for porosity or defects that .may be caused by injury during theprocess of manufacturing such bodies. More particularly the invention relates to the testing of tubes of the'form of an annulus which are'composed of a flexible elastic material, such as rubber and the like, used as an inneraair-container for :pneuimatic tires and the like.

Previous apparatus for testing tubes by sub.- merging in a liquid were adequate for tubes having a cross-sectionaldiameter up to seveninches, or inner tubes used in passenger-car tires,. but they do not possess the. capacity to test tubes of large cross-sectional diameter such as used in tires for trucks, buses, tractors and earthem'oving vehiclessome of which require-inner tubes having. a cross-sectionaldiameter of 24 inches when inflated. Tubes of this character are-.intheform of an annulus, and the term cross-section. used herein is defined by a section taken on a line which is normal to the generating axis of the annulus.

Prior practice in testing tubes of thenlargerrsizes has been to partially innate them, then. lease them in this inflated condition for. aperiod oi time to determine if any 'of the inflating fluid had escaped. This process did-.no't reveal the location of the leak .so defective tubes were again inflated to ahigher pressure inorder to locate and repair the defect.

An object of the. resent invention is; to provide an apparatus that will submerge .andimanipnlate tubes. of the larger sizes, :such as are used; on trucks, buses, tractors and earthemoving. vehicles, .or tires generally referred toas oft-theroad tires.

Another object of this inventionis' to provide a device [possessing sufficient .force to submerge tubes of large cross-sectional diameter, some of which require a thrust of 1400 pounds; to be properly submerged, stretched and held. while being tested.

Another object of the invention is to'provideian apparatus that Will automatically submerge, radially stretch andLrotate partiallyinflated tubes efficiently with a minimum Ioft time: and labor without injury to the tubes, one. whichiseasy to operate, simple in. construction. and capable of handling a wide range of sizes.

The aforesaid objects of .the invention, and other objects will: become apparent as-the ole-- scription' proceeds. For a better understanding f the invention reference: should be had to the accompanying drawings "wherein:

Eigure .1 is a side elevation of the apparatus showing the arms in 'a'contracted' position;

2 is .an end elevation showing the arms in a. partially expanded position;

Fig. 3' is an enlarged view taken on the: line 3'--3'of1Fig. 2.;

Fig. 4 is a, detailedview of one of the arms;

Fig. his a view taken substantially on the line iiii Fig. 4;,

Fig; 6 .isa view ofthesize-i'ndicating device;

Fig. 7 is. a plan view' of the apparatus;

Fig. 8 .iswa side view taken. on the line 8-8 of Figure l of the solenoid-operated val vefor rais .ing ands-lowering the carriage;-

liig. 9 is a, piping diagram; and

10'. is a wiring diagram.

Although the principles of "the invention are broadly applicableto' testing tubes of large crosssectional diameter, the invention is also applicable. to the testing of the smaller and all intermediate sizes.

With specific reference to-the formof the inventionillustrated in the drawings, the numeral .l'. indicates an opentopped liquid-containing vessel or tank cylindrical inform. Liquid is sup: .pliedvto the tank through a supply line '2', a drain line 3 is provided to drain the liquid from the tank when not in use.

A structural-steel frame-work 4 comprising a pair of vertical members 5 positioned diametrically opposite one another with respect to said tank are tied together at their upper ends by-apair of cross-members B. Centrally mounted on topof thecro'ss-members and attached thereto by the bolts T a rectangular plate 8 has suspended from each: corner thereof fluid-pressure cylinder 9.

The cylinders 8, identical in construction, have theirlower flanged'ends extending through open--v ingsi'n a plate or platform Iii.

Disposedwithin the cylinders- 9 are doubleacting pistons H attached to piston rods i 2 which extend downwardly to a spider plate 13 to which they are securely attached.

The spider plate 1 3 forms the-body member of a carriage indicated generally by the numeral M which is raised and lowered by the action of the pistons it within the cylinders 9.

Aiding the piston rods 12' in keeping the car riagein alinement on its vertical up-and-down movement are a pair of guides, which consist of tubular members i5 which are attached toeach cross-member E and iplat'e It of the frame, and a pair of' rods I 5 attached to the spider plate in sliding relationship in said "tubes.

The spider plate I3 is circular in form having a boss ll formed centrally on its lower side from which ribs 53 extend radially beyond the outer periphery of the plate terminating in the form of bosses I9, to which arms 20 are pivotally mounted by the pins 2i. Six arms of identical form are thus connected to the spider plate that serves to submerge and manipulate pneumatic tubes, as will be described later.

The main body of the arms '25 are of channel shape in cross-section, the upper ends of which terminate in bifurcated lugs 22 which embrace the bosses l9 extending from the spider plate l3, forming hinged connections by the pins 21 as illustrated in Figs. 1, 2 and 4.

As best illustrated in Fig. 4, the arms 25 are provided with bearings 23 and 25. The upper bearings 23 are formed by bosses extending from ribs 26 which are formed across the bight of the channel-shaped portion of the arms 20. The lower bearings 24 are formed by conical terminations 2! at the lower ends of the arms. Shafts 28 mounted to revolve in said bearings are extended through the lower bearings 25 to receive flaring rollers 29, which are attached to the lower end of said shafts by set screws 35. It is advantageous to flare the rollers at their upper ends so that their outer contours will substantially follow the contour of the tubes being tested to more readily control the tubes while being tested.

Attached to the lower end of the channeled portion of the arms 25 as illustrated in Figs. 1, 2 and 4 is a bracket 3! having end portions 32 turned at right angles to the body thereof. To each end portion are bolted similar brackets 33 also having end portions extending at right angles to the body thereof. The end portions are bored to receive shafts 34 on which are mounted rollers 35 which cooperate with the flared rollers 29 to submerge and manipulate tubes while being tested.

It will be noticed that the rollers 35 are slightly tilted upward so that their axes are at an angle slightly greater than a right angle with respect to the axes of the flaring rollers 29. This angular relationship tends to minimize the distortion of the tubes when held by the rollers.

When a partially inflated tube or other article is tested for porosity, or other leaks which may be caused by injury during the course of manufacture, the test is rendered more effective by stretching or tensioning the walls of the article.

The stretching or tensioning of the article is accomplished in the following manner as illustrated in Fig. 2. Mounted upon the spider plate l3 and becoming a part of the carriage 54, a fluidpressure cylinder 36 has disposed therein a doubleacting piston 31 mounted on the upper end of a piston rod 38. The other end of the piston rod has mounted thereon a spider block 39. Radiating from the outer periphery of the block 39, bifurcated lugs 40 receive the single end of forked links 4| which are pivotally mounted thereon by pins 42. The forked end of the links il extend obliquely downward, the fork straddling the lower end of the channeled portion of the arms 25 and is pivotally connected thereto by the pins 43.

For the purpose of illustration water is used as a fluid-pressure medium in the cylinders 9 and 36, but other fluid may be used if so desired.

The carriage I4 is lowered by admitting fluid to the upper end of the cylinders 9. The carriage with arms 20 contracted as shown in Fig. 1 is carried downwardly; as the arms 25 approach the opening of the annulus they begin to spread 4 so that the rollers 29 and 35 will properly engage and stretch the tubes during the submerged period.

The cylinders 9 are operated by a solenoid-operated valve, the down movement of the carriage being stopped when a contact arm 44, mounted on top of the cylinder 36, contacts an electric stop-switch 45 mounted on the platform II]. To stop the upward movement of the carriage the arm 44 contacts the stop-switch 46 attached to the upper part of the frame work 4.

It is important to stretch partially inflated tubes so that their walls will be in tension while submerged, otherwise a limited degree of porosity may not be revealed due to the limited pressure within the tubes.

It has been established that a radial stretch, equal to approximately 40% of the inner diameter of the annulus being tested, will be suificient to reveal any porosity that may exist in the walls of tubes of the character herein under consideration.

To provide each size of tube the same proportionate stretch an indexing means, which operates'in conjunction with a pair of limit switches, automatically controls the extent of spread of the arms 25 when the rollers 29 and 35 are in engagement with the tubes.

The stretch or distortion-controlling means (see Figs. 1 and 2) is composed of a bracket 41 attached to the platform Iii. Said bracket terminates in a downwardly extending vertical arm 48, to which is attached a switch-contact member 49 having formed thereon a rounded cam surface 50 which is engaged by a contact arm 5| of a switch 52 during the downward course of the carriage [4. This contact actuates a solenoid-operated valve which admits fluid to the upper end of the cylinder 36. This will drive the spider block 39 downwardly, whereby the arms 20 begin to spread by the action of the links M.

The spreading of the arms continues as the carriage moves downwardly until a contact arm 53 carried on the spider block 39 engages a contact arm 54 of a switch 55, which closes a solenoid-operated valve to stop the spread of the arms 20. This carriage M continues downwardly until the stretched tube is properly submerged. The limit of the downward movement of the carriage M is controlled by the contact member 44 contacting the arm of the limit switch 45 mounted on the platform It. The submerged tube is held in this position for a predetermined period of time, then released by a reverse action of the values and cylinders as will later be described. The switches 52 and 55 (see Figs. 2 and 6) which control the spread of the arms 29 and the stretch of the tubes, are mounted on a slide 56 which slides up and down on the vertical arm 5! of a bracket 58. (See Figs. 1, 2 and 6.) The slide comprises a pair of plates 59 and 65 which are grooved to receive the vertical arm of the bracket 58 and held together by the bolts 6!. A thumb screw 62 passes through the plate 59 and contacts the vertical arm to lock the slide in place When set in the desired position. A calibrated bar 63, having numerals on the face thereof which correspond to the inside diameters of the tubes being tested, is attached to the vertical arm 51 of the bracket 58 .by brackets 64 and 65. A pointer 65 is attached to the slide 56 which indicates the sizes of tubes to be tested. For instance, if tubes having an inside diameter of 28 inches are to be tested, the pointer will be set at the numeral 28 on the'calibrated bar 63.

sumac-ac Mounted on; the: bracket-.158; are; bearings 81 andrfit which receive shafts. and 10,. on which are mounted sprocket wheels H and 12.. These sprocketsiare. embraced: by aychairr. :13; The ends of the chain are attachedto; the slide 56.. Also mounted on the shaft. It is a hand. wheel 14 which, when. revolved; causes; the slide, on which the 'limitswitch'es fii .and: 5.5 are mounted, to be moved: along the vertical' arm '51. Thiswill :perunit the limit. switches tov %be; positioned. the proper distance from the cam surface 55. :on the bracket 41 and the contactarmi53 so that the various sizes of :tubes will. "be given. the proper proportionate stretch according to their inside diameters, which. :will be indicated by the pointer 66-.

To. check thev jar caused when. the carriage reachesiits extremedownward position; a cushioning device is employed- (see Fig. 11):. The device-comprises a cushion of. rubber 15. of cylindrical form positioned between a pair of washers "l6 and 17, an eye bolt 18 extends axially. through the cushion and washers and is attached thereto by anut is. The cushioning device is mounted on *the rectangular plate 8 centrally located with respect tothe arm-spreading cylinder 36. The eye ibolt extends through an opening in the plate 8 and has attached to the eyethereof a chain 80. The other end of the chain extends to the top of the cylinder '38 and is attached to an eyebolt 81 secured in a plate 8-2 mounted on the cylinder 36. The chain is of the properlength to permit the cushioning device tobecome effective just before the carriage reaches its extreme downward motion'to ease the shock and prevent possible damage to-the apparatus.

When the carriage is in itslower-most position, the tube being tested in a radially stretched or distorted form and entirely submerged, theapparatus comes to rest. Inthis position the tube is observed for leaks which if present are located by tell-tale bubbles which rise to the surface of the testing fluid in the tank in which the tube is submerged. If leaks appear they are marked for location and later repaired or rejected as defective, depending on the degree of the defects.

When a tube is properly submerged and stretched the-tube isheld -by the rollers 29 and 35 tightly enough 'to seal any porosity in-the portions of the tube which are in contact with the supporting rollers. For this reason it is necessary to revolve the tube far enough to relieve these surfaces so that they will be exposed for test.

The tubes are revolved by theflaredrollers 29 which are actuated by fluid-pressure means in cooperation with a rack and pinion mounted on theupper end of the channel portion of the arms 2ll inthe following manner.

Welded or otherwise attached to the upper end of the channel portion of each arm- 20, metal bars 83 and 81! have offset portions 85 and 85 to which metal strips 8"!- and-88 are attached by cap screws 89 and '90" These metal bars and strips cooperate to form slideways 91 to receive plates 92. (See Figs. 3, 4 and-"5.)

On. one side of. said plates 92 a. groove '93 is formed to receive racks 95, which are secured- 92. (fluid-pressure cylinders 98 are attached thereto; by capscrews 99.

The cylinders .98 have disposed therein doubleactingpistons more. 'whichmre'attached. piston rods. In I. The outer; ends orfthe: piston. rods'ex tend to. bosses Hi2 formed on angular brackets 103 which are attached; tov the-warmsv 20'. The piston :rodsv are rig-idly attached to the brackets by cap screws ltd extending through the bosses I62 and screwed into tappedholesprovided in ends of the piston rods HH, so. that. when fluid pressure is admitted to the cylinder the piston remains stationary, permitting, the" cylinders; to move,v thus causing the plates. 92 to slide in the grooves or :slideways 9!, which will cause the shafts 28 and rollers. 29 to; revolve in either direction through the action of the racks. 9.5. and pinions 91 The direction of: rotation-depends on into which end of "the cylinders the fluid pressure is admitted.

For the purpose of. illustration, air is used to operate the pistons l-llcwithin the cylinders 98.

The cylinders -98 are actuated by the manipulation of a valve its attached to-the sideof the tank The valve is a commercial article and has connected thereto an inlet conduit it! which extends to a source of fluid supply under'pressure, outlet conduitsv 118.3 and [09, an exhaust port Hi) and an operatinglever H-l.

As illustrated in Figs. 1 and 3 the conduit H118 extends from the valve I06 around the tank ,I to one of the vertical members. 5 and extends upward therealong, terminating with; a connection M2. to which a flexible hose H3 is attached. The hose extends to a manifold H4 which is provided with suitable connections, to which are attached lengths of flexible hose H5 which extend to one end of the cylinders.

The conduit Hi9 extends to. the opposite; vertical member 5 then upwardly and terminates in a connection [it to which is attached .a flexible hose lil, which extends to :a. manifold. H from which are extended flexible hose 9; which by suitable connections are attached to the, other. ends of the cylinders 93;

The manifolds 1 I 3 and [1.8 are in' the form of the greater part of a circle and areattachedto the upper side of the spider plate l3;

Thus it will be apparent that byrthe, manipulation of the valve lever l H fluid under pressure may be admitted to either end of: the cylinders 98 which, dueto the fact that the pistons remain stationary, cause the cylinders. to move in either;

direction, which in turn causes the plates 59.2, to. which the cylinders are attached, to slide in the slideways 9|. This actuates the. racks 9.5 which are attached to the opposite side-of the plates e2. The movementof the racks drives the pinions 9! which are mounted on the shafts. 28 tov revolve the rollers 26 which in turn. revolves'the.

tube being tested? to expose any porosity that may exist at points where the first contact was made between the "tube and the rollers 29 and-35.

The valves for'suppl'ying i'iuidunder pressure to the four cylinders 9 which raise and lower the carriage l iand the single cylinder t't'whichcontrols thespread of the arms 28: are 4-way double solenoid-operated valves of'identical.conventional form which may be procured in units as illustrated in Fig. 8. The units comprise .a framev l3 l. in which are mounted a valve l2! and a pair of solenoids 12:3:and. which operate either side of the valveithrough suitable linkage as will now be described in conjunction with thepipingzdiagrain as illustrated in Fig. :9.

Referring to Figs. '8 and9, a supply line L2H} extends from a source ofyfiuidsupply underpressure (not shown) tothe, valve 121]. This valve supplies fluid under pressuratlo thez-founcylindersi 7 9 which serve to raise and lower the carriage I4. When a switch I22 attached to the tank (see Fig. 1) is closed, through a coil and relay the solenoid I23 is energized causing the bell crank I24 to depress the plunger I25. This permits fluid to flow through the outlet conduit I26 to the top of cylinders 9. At the same time the op= posite side of the valve is open to the conduit I21 and the drain line I28 which permits fluid to escape from the lower ends of the cylinders 9.

This will cause the carriage I4 to move downwardly. When the arm I of the switch 52 (see Fig. 2) contacts the cam 55 mounted on the arm 48 the solenoid I29 is energized, which actuates the bell crank I30 to depress the plunger I3I of the valve I32. This permits fluid to flow through the branch supply line I33, through the valve and flexible conduit I34 to the upper end of the cylinder 36. This will cause the arms 20 to spread until the contact arm 53 contacts the arm 54 of switch 55 (see Fig. 2), which terminates the spread by deenergizing the solenoid I29. When the solenoids are deenergized the valves automatically return to a neutral position.

After a predetermined period of time, due to a time switch, in which the tube is held in a submerged and radially stretched position, the switch I35 on the opposite side of the tank is depressed. This actuates the proper coil and relays to energize the solenoid I36 which actuates the bell crank I31 to depress the plunger at the opposite end of the valve I2I to permit fluid to flow from the valve I2I through the conduit I21 to the lower end of the cylinders and at the same time permit fluid to drain from the upper ends of the cylinders through the conduit I25 through the valve and into the drain conduit I28, to permit the carriage to raise.

At the same time the carriage is raised the solenoid I39 is energized, which actuates the bell crank I45 to depress the plunger I3I of the valve I32. This supplies fluid under pressure from the valve I32 through the flexible conduit I45 to the lower end of the cylinder 36 and permits fluid to drain from the upper end of the cylinder 35 through the flexible conduit I34 through the valve I32 then into the drain conduit I4I. This allows the arms to retract while the carriage is being raised. As the cylinder 36 travels with the carriage it is necessary that flexible conduits I34 and I43 in the form of hose be used to connect the valve I32 with the cylinder 35.

The electric circuits for controlling the apparatus are shown in the wiring diagram of Fig. 10. In the diagram current is supplied from the main feed lines I42 and 543, 440 volts is required to operate the solenoids but 110 volts is used to operate all other contacts, therefore a, transformer I44 is provided in the main supply lines.

When the carriage I4 is in its uppermost position and the arms 25 retracted the apparatus is in its neutral position the switch I22 is closed thereby closing the line I45 which leads to a relay coil I45, which in turn closes the relay MI in the shunt line I48. This permits current to pass through the lines I45, I49 through the transformer I44, then lines I50, I5I and I52 to the multiple relay I53 which actuates the solenoid I23. This actuates the valve l2I to permit fluid under pressure to flow to the upper end of the cylinders 9 which will lower the carriage I4. The carriage on its downward course causes the cam surface 58 to contact and close the switch 52 which energizes the relay coil I55 in the line I55. This in turn closes the relay I51 on the shunt line I58 which starts the arms 20 to spread by current passing through the lines I49, the transformer I44, lines I5I and I59 to the multiple relay I55. This energizes the solenoid I29 which actuates the valve I32 to admit fluid to the upper end of the cylinder 36. The spread of the arms is stopped when the contact member 53 contacts the switch arm 54. The carriage continues downwardly until the contact member 44, attached to the top of the cylinder 36, contacts and opens the down limit switch 45 which is attached to the platform I0. This opens the line I45.

At the same time the coil I46 is energized a coil I6I in the line I52 opens a switch I53 in the line I54 which in turn opens a time delay switch I65 in line I65. The time delay switch is set to close in a predetermined period of time (about 12 seconds), during which time the carriage cannot be raised. This is to assure sufficient time for the tube to be properly tested before being released. When the time has elapsed the time delay switch closes causing the light IB'I to signal that the carriage may be raised.

To raise the carriage I4 and retract the arms 20 the switch I35 is closed. This energizes the coil I58 in line I59, also the coil H5 in line Ill, and closes the relay H2 in line I'I3. This directs current through the lines I69, I49, I5I and I14 to the multiple relay Il5 to actuate the solenoid I33 which in turn actuates the valve I2I so that fluid is directed to the lower ends of the cylinders 9 to raise the carriage.

Simultaneously current is directed through the lines Ill, I49, I5I and I16 to the multiple relay Ill to actuate the solenoid I39 which in turn actuates the valve I32 to direct fluid under pressure to the lower end of the cylinder 35 to retract the arms.

At the same time the switch I35 is closed the normally closed relay I'I8 opens to cut off current to the circuits which cause the carriage to be lowered. This will permit the contact member 55 to pass the contact arm 5I of switch 52 in its upward course so that the retraction of the arms will not be interrupted.

The limit of the upward movement of the carriage is controlled by the contact member 44 located on top of the cylinder 36 contacting the up limit switch 45 attached to the upper part of the frame which opens all lines, at which time the apparatus is in neutral position, ready to repeat the cycle.

For safety to the operators and to prevent damage to the apparatus or the article being tested, emergency switches 5'59 and I83 of the pushbutton type are provided in the feed line I64, whereby the apparatus may be stopped or raised at will, the switch I79 normally closed may be opened to stop the apparatus. The switch I85 normally open may be closed to raise the carriage to a neutral position. Even though it is believed the operation of the apparatus will be apparent from the foregoing description, a brief review thereof will now be made for the purpose of summary and simplification.

The cycle of operation of the apparatus, including the duties of the operators, is as follows:

The tubes are delivered to the apparatus in a deflated condition. There are two operators required to operate the apparatus, one at the front and the other at the rear side. The operator at the front of the apparatus inflates a tube so that it is well rounded out and the wall is slightly in tension. He then places the tube centrally in the tank, then depresses the push button of the '59? switch 122 (see' Flg. "1) which will start the carr ia'ge downwardly. As the rollers 29 enter the opening oi the tube the-cam member 50 contacts the arm-'51 "of switch '52 (see Fig. 2) which starts the arms 20 to spread, the rollers 35 then contact the upper surface of the tube to submerge same. The stretching of the tube continues until the-contact arm 53 contacts the arm is of switch 55. The carriage continues downwardly until the "contact member 44 on the cylinder 36 con-- tacts the limit switch '45 to bring the carriage to rest in its lowermost position, at which time the operators observe the tube for leaks. The front operator then manipulates the lever iii of valve 106' which will rotate the "tubes to reveal hidden porosity that may be concealed at the original points of contact between the tubeand rollers. The operatorsagain observe the tube for porosity. After a few seconds the light Eel will show, indicating that the carriage may be raised. The rear operator then depresses the push button of switch 135 which serves to set in motion the mechanism to raise the carriage; as the carriage raises the arms '20 retract, releasing the tube which, when free, is removed from the tank by the rear operator. The carriage raises until the contact member 44 contacts the contact arm of the switch 46 to bring the carriage to rest in its neutra1 position ready for another cycle.

From the foregoing description, it will be apparent that an apparatus of a practical nature, convenient to operate, and efficient in operation has been produced by the present invention. From its automatic nature, it will save time and by its use a more dependable product will be produced.

While in accordance with the patent statutes one'best-known embodiment of the invention has been illustrated and-described in detail, it is to be particularly understood that the invention is not limited thereto or thereby, but. that the inventive scope is defined in the appended claims.

I claim: v

1. An apparatus for testing annular elastic pneumatic tubes comprising an open-topped liquid-containing vessel, a carriage, fluid-pressure actuated cylinders for raising and lowering said carriage. in a vertical path to submerge said tubes, a series of arms suspended from said carriage, a fluid pressure actuated cylinder for spreading said arms to stretch said tubes, and rollers mounted on the lower ends of said arms to engage and rotate said tubes.

2. An apparatus for testing inflatable annular elastic tubes comprising an open-topped liquidcontaining vessel, means for submerging an inner tube in said liquid, said means comprising a carriage suspended above said vessel, hydraulic means for raising and lowering said carriage, arms swingably suspended from said carriage, hydraulic means for radially spreading said arms, and rollers mounted at the lower ends of said arms for manipulating said tube while submerged.

3. An apparatus for testing inflated inner tubes for pneumatic tires comprising an open-topped liquid-containing vessel, means for vertically submerging a partially inflated inner tube, said means comprising swingably mounted arms suspended above said vessel, fluid pressure means for lowering and raising said arms and roller means disposed on said arms for submerging and manipulating the tubes to disclose leaks therein.

4. An apparatus for testing inner tubes for pneumatic tires and the like comprising a liquidcontaining vessel, a carriage suspended above said vessel, fluid-pressure means for lowering and raising said carriage, arms swingably suspended from said carriage, fiuid-pressure-mea'ns for spreading said arms radially when the carriage is on its downward movement-and retracting the arms on their upward movement, and roller means for submerging and manipulating the tube during the testing thereof.

5. An apparatus for testing annular inflatable elastic tubes comprising an open-topped liquid containing vessel, a carriage having a body member centrally suspended above said vessel, arms pivotally connected about the periphery of the body of said carriage, fluid-pressure means for lowering and raising said carriage to submerge and release a tube, fluid-pressure means for spreading the arms outward to stretch the tubes and a fluid-pressure means which actuatesa rack and pinion to rotate the tube while submerged'in the testing liquid.

6. An apparatus for testing inflatable annular elastic tubes for pneumatic tires comprising an open-topped liquid-containing vessel, a-irame, a carriage suspended from said frame above the liquid, fluid-pressure means for actuating said carriage, arms pivotally suspended from said carriage, a series of rollers extending laterally" from said arms to submerge a tube in said liquid, another series of rollers extending axially f-rorn said arms, means for rotating said rollers embodying fluid-pressure cylinders in cooperation with racks and pinions, and a time limit means to submerge the tubes for a predetermined periodof time.

7. An apparatus for testing annular inflatable inner tubes comprising a liquid-containin vessel, a carriage suspended centrally above said vessel, fluid-pressure actuated cylinders for raising and lowering said carriage, a spider plate formingthe body of said carriage, a series of arms pivotally suspended from the periphery of said spider plate, a fluid-pressure actuated cylinder for radially spreading and retracting; said arms and rollers attached to said arms to engage and manipulate the tubes while being tested.

8. An apparatus for testing annular resilient inflatable inner tubes, comprising a liquid containing vessel, a support, a carriage suspended from said support above said vessel, fluid-pressure actuated cylinders for lowering and, raising said carriage in a vertical path, a spider plate forming the body of said carriage, a series of arms pivotally suspended about the periphery of said. spider plate, a series of rollers extending substantially horizontally from said arms to submerge a tube, a series of rollers extending axially from said arms to engage and radially stretch the tube and fluid-pressure actuated cylinders carried by said arms to rotate said axially extending roller to rotate said tube to disclose defects therein at the previous points of contact with said rollers.

9. An apparatus for testing inner tubes for pneumatic tires comprising a liquid-containing tank, a frame work support, a carriage suspended from said support, a plurality of fluidpressure cylinders mounted on said frame work support for raising and lowering said carriage, a spider plate forming the body of said carriage, a series of arms pivotally mounted about the periphery of said spider plate, a fluid-pressure cylinder mounted on said spider plate to spread and retract said arms, a series of rollers extending substantially horizontally from said arms to submerge the tubes, a series of rollers extending axially from said arms to engage and radially stretch the tubes and fluid-pressure means to actuate racks and pinions for revolving said axially extending rollers to rotate the tubes while submerged.

10. In a, pneumatic tube-testing apparatus of the type described, a liquid-containing tank, a frame work support, a carriage suspended from said support, a plurality of pressure cylinders mounted on said frame to lower and raise said carriage, a solenoid-operated valve mounted on said support to admit fluid to said cylinders, a spider plate forming the body of said carriage, a series of arms pivotally suspended irom the periphery of said spider plate, a fluid-pressure cylinder mounted on said spider plate, a piston rod extending from said cylinder, a spider block attached to said piston rod, links extending from said spider block to said arms, a solenoid-operated valve mounted on said frame work to admit fluid to said cylinder to spread and retract said arms through the action of said piston rod, spider block and links, rollers extending axially from said arms, and means for revolving said rollers torotate said tubes while submerged, said means comprising racks and pinions actuated by fluid pressure cylinders.

11. 'In an apparatus for testing inner tubes for pneumatic tires, a testing-liquid-containing tank having an open top, a carriage centrally suspended above said tank, fluid-pressure cylinders to raise and lower said carriage to submerge the tubes, arms pivotally suspended from said carriage, a fluid-pressure cylinder mounted on said carriage to radially spread said arms, fluidpressure cylinders carried by said arms to rotate the tubes, a solenoid-operated valve to supply fluid to the cylinders for raisin and lowering the carriage and another solenoid-operated valve to supply fluid to the cylinder to radially spread and retract the arms.

12. In an apparatus for testing annular pneumatic inner tubes, a liquid-containing vessel, a carriage suspended above said vessel and centrally thereto, a plurality of fluid-pressure cylinders to raise and lower said carriage to submerge a tube, said cylinders being actuated by a solenoid-operated valve, a series of arms suspended from said carriage, a fluid-pressure cylinder mounted on said carriage, a solenoidoperated valve to actuate said cylinder, a piston rod extending from said cylinder, links connecting said piston rods to said arms to radially spread and retract said arms to stretch and then release the tubes, and fluid pressure actuated rollers mounted on said arms to rotate said tubes while submerged.

13. In an apparatus for testing annular pneumatic tubes, a liquid-containing tank, a carriage suspended centrally above said tank, a plurality of fluid-pressure cylinders to raise and lower said carriage in a vertical path to submerge said tubes in said liquid, said cylinders being actuated by a solenoid-operated valve, a series of arms carried by and suspended from said carriage, a fluid-pressure cylinder carried by said carriage, a solenoid-operated valve to actuate said cylinder to spread said arms to stretch said tubes, and retract the arms to release said tubes when tested, and fluid pressure actuated racks and pinions to rotate a plurality of rollers attached to said arms to engage and rotate said tubes while submerged.

14. An apparatus for testing annular pneumatic inner tubes comprisin an open-topped liquid-containing vessel, a vertically reciprocable carriage suspended above said vessel, fluid-pressure means for eflecting reciprocal movement to said carriage, expander means comprising a plurality of fluid pressure actuated arms pivotally suspended from said carriage, angularly disposed roller means extending from said arms to engage the upper wall of a tube ulpon lowering said carriage to submerge the same, roller means disposed axially on said arms for engaging the inner wall of a tube for radially stretching and holding the same while submerged, and fluid pressure actuated racks and pinions to rotate said last-named rollers and the tube engaged therewith when fully submerged.

WILLIAM H. GERSTENSLAGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,695,979 Reid Dec. 18, 1928 1,854,556 Moebes et a1. Apr. 19, 1932 1,863,764 Prentice June 21, 1932 1,908,311 Branick May 9, 1933 2,135,681 Smith et al. Nov. 8, 1938 

